1. Technical Field
The present invention relates to a display device with a position detecting function and an optical position detecting device, and an electronic apparatus having the display device with the position detecting function.
2. Related Art
Recently, in electronic apparatuses such as a cellular phone, a car navigation device, a personal computer, a ticket vending machine, and a bank terminal, a display device with a position detecting function has been used in which a touch panel is disposed on a front surface of an image creating device such as a liquid crystal device. In the display device with the position detecting function, an information input is performed by referring to an image displayed on the image creating device. The touch panel is provided as a position detecting device which detects a position of a target object inside a detection region.
As a detection method of the position detecting device, there are known various methods using a resistive film, an ultrasonic wave, an electrostatic capacity, an optical system, and the like. In the method of using the resistive film, the cost is low, but the permeability is low like the method using the electrostatic capacity. In the method using the ultrasonic wave or the electrostatic capacity, the response speed is high, but the environment resistance is low. On the contrary, in the method using the optical system, it is characterized in that the permeability and the response speed are high (refer to JP-A-2004-295644 and JP-A-2004-303172).
However, in the optical position detecting device disclosed in JP-A-2004-295644 and JP-A-2004-303172, a light receiving element is attached to the outside of an electric optical panel. For this reason, there is a problem in that a size in the thickness direction or the external shape of the optical position detecting device increases by at least a space used to dispose the light receiving element. In addition, in the configuration in which the light receiving element is attached to the outside of the electric optical panel, there is a problem in that a cost increases.